1. Field of the Invention
The present invention relates to an ink tank for storing an ink used in an ink jet recording apparatus and a production process for the ink tank.
2. Description of the Related Art
An ink tank used in an ink jet recording apparatus is constructed detachably from the recording apparatus to facilitate replacement when ink has been consumed.
Such an ink tank has a casing 501 storing an ink and a joint member 502 for joining the tank to a recording apparatus body like an ink tank 500 described in Japanese Patent Application Laid-Open No. 2009-298153 and illustrated in, for example, FIG. 7. The ink tank 500 is fixed by welding an outer peripheral edge of the joint member 502 to the casing 501 of the ink tank.
As described above, the joint member of the conventional ink tank forms a “weld ridgeline” along the outer peripheral edge by being welded at its outer peripheral edge, so that the “weld ridgeline” tends to become long as the size of the ink tank becomes large.
However, when an engaged portion with a connection member of the recording apparatus is arranged in the inside of the “weld ridgeline” with the outer peripheral edge of the joint member regarded as the “weld ridgeline” as described above, the reliability of seal property at a welding portion is lowered as the length of the outer peripheral edge forming the “weld ridgeline” becomes long when the ink tank is enlarged. The lowering of the reliability of seal property at the welding portion may cause such a problem that it cannot withstand impact upon falling to cause ink leakage.